A partitioner that takes start and end keys and uses bigdecimal to figure
which reduce a key belongs to. Pass the start and end
keys in the Configuration using hbase.simpletotalorder.start
and hbase.simpletotalorder.end. The end key needs to be
exclusive; i.e. one larger than the biggest key in your key space.
You may be surprised at how this class partitions the space; it may not
align with preconceptions; e.g. a start key of zero and an end key of 100
divided in ten will not make regions whose range is 0-10, 10-20, and so on.
Make your own partitioner if you need the region spacing to come out a
particular way.